1. Field of the Invention
The present invention relates to image forming apparatuses, and more particularly, relates to an image forming apparatus which can carry out an image reading operation for image data in parallel with an image forming operation for image data.
2. Description of the Related Art
An image forming apparatus having a so-called multi-job function has been known. The multi-job function allows the image reading operation for image data of a first group of original documents to be synchronously carried out in parallel with the image forming operation for image data of a second group of original documents which is different from the first group of originals. Such an image forming apparatus is structured such that the image reading and image forming operation being executed is discontinued by, for example, warning of the paper empty, jam and the like, malfunction of the apparatus itself, an interruption which makes an image forming operation to be executed by interrupting a job (image forming operation for one group of original documents) being executed, and the like.
Regarding such an image forming apparatus, U.S. Pat. No. 5,239,388 discloses the following image forming apparatus. In this image forming apparatus, image forming operation for a job being executed is discontinued when some malfunction occurs, determination is made as to whether the malfunction belongs to an automatic recovery category or to a manual operation recovery category, and control is made such that the discontinued image forming operation is automatically resumed when a factor of the malfunction is removed if the malfunction belongs to the automatic recovery category, and the image forming operation is not resumed until a proper manual operation is carried out even if a factor of the malfunction is removed when the malfunction belongs to the manual recovery category.
In the case of the image forming apparatus having the multi-job function, when a malfunction belonging to the manual recovery category as described above occurs, even if a factor of the malfunction is removed, a user who has registered the image forming operation to be resumed at this time is not always present near the apparatus. The user who has registered the image forming operation to be resumed is supposed to have registered the operation in advance by an image reading operation and the like.
Accordingly, sometimes the user carries out no proper manual operation for resuming the image forming operation, and the image forming operation is left discontinued for a long time.
Then, when the image forming operation is discontinued due to any warning, malfunction, interruption and the like in the image forming apparatus, in some cases the image forming operation needs to be resumed automatically at the time of removal of the factor of the discontinuation.
Japanese Patent Laying-Open No. 4-2188 discloses an image forming apparatus in which, when the interruption above is set, the interruption is automatically canceled if no operation is carried out for a definite time, and an image reading operation and an image forming operation that are discontinued due to setting of the interrupt operation are automatically carried out.
As for a general image forming apparatus, a user brings some original documents to be set for an image reading operation, executes an operation for starting, and takes away the original documents when the image reading operation completes. In other words, the user attends the image reading operation in most cases.
In this case, if the operation is discontinued due to any warning, malfunction, interruption and the like, especially if the operation is discontinued due to jam of the original documents being read, the user may handle the set documents while the operation is discontinued.
If an image forming apparatus is structured such that the image reading operation is automatically resumed when a factor of discontinuation is removed, the user attending the image reading operation may feel uneasy in the case described above.
In some cases, when the image reading operation is discontinued due to any warning, malfunction, interruption and the like in the image forming apparatus, the automatic resuming of the operation may be less convenient for the user.